Preparation of polyamide with catalyst comprising transition metal attached to a ligand which contains electron withdrawing groups

Abstract

A novel transition metal complex catalyst comprised of a transition metal attached to a ligand containing electron withdrawing substituents is employed in a polymerization process for producing nylon type polyamides.

The claimed invention is: 
     
       1. A process for producing a nylon type polyamide, containing a plurality of ##STR11## amide groups as integral parts of the main polymer chain, comprising contacting at a temperature sufficient to cause polymerization, at least one polyamide forming reactant with a transition metal complex catalyst, wherein the catalyst comprises at least one transition metal attached to a ligand containing electron withdrawing substituents wherein the electron withdrawing substituents are selected from the group consisting of --F, --Cl, --Br, --I, --CF 3 , ##STR12## --CN, --NH 3   + , --NO 2 , and --NR 3   +   where R is an alkyl or an aryl radical. 
     
     
       2. The process of claim 1, where the transition metal in the catalyst is selected from the group consisting of cobalt, molybdenum, nickel, copper, iron, manganese, ruthenium, chromium, vanadium and rhodium. 
     
     
       3. The process of claim 2, where the transition metal in the catalyst is selected from the group consisting of cobalt, molybdenum, nickel and copper. 
     
     
       4. The process of claim 1, where the valence state of the transition metal in the catalyst is greater than or equal to +2. 
     
     
       5. The process of claim 1, where the ligand is organic and has a net negative or neutral charge. 
     
     
       6. The process of claim 1, where the electron withdrawing substituents attached to the ligand have a positive Hammet coefficient. 
     
     
       7. The process of claim 1, where the ligand is organic and has a net negative or neutral charge. 
     
     
       8. The process of claim 6, where the organic ligand includes oxygen, nitrogen, sulfur, phosphorus, arsenic or mixtures thereof. 
     
     
       9. The process of claim 8, where the ligand is selected from the group consisting of ##STR13## where X is an electron withdrawing substituent and R is an alkyl or aryl group. 
     
     
       10. The process of claim 1 where the transition metal complex catalyst is selected from the group of consisting of cobalt (II) trifluoroacetylacetonate, cobalt (III) trifluoroacetylacetonate, cobalt (II) hexafluoroacetylacetonate and cobalt (III) hexafluoroacetylacetonate. 
     
     
       11. The process of claim 1, where the transition metal complex catalyst is employed in conjunction with a cocatalyst selected from the group consisting of: (a) di-sec-butylmagnesium;   (b) n-butylmagnesium chloride;   (c) aluminum triethyl and   (d) compounds of the formula:   (R.sup.VI).sub.n AlX.sub.(3-n)        where R VI  is at least one of an aliphatic, cycloaliphatic or aromatic radical of 1 to 8 carbon atoms,   X is halide and   n is less than or equal to 3 but greater than 0.     
     
     
       12. The process of claim 11, where R VI , in the cocatalyst of the formula (R VI ) n  AlX.sub.(3-n), is at least one of an alkyl, aryl, arylalkyl, alkenyl, or arylalkenyl radical. 
     
     
       13. The process of claim 12, where R VI  is at least one of an ethyl, isopropyl, sec-butyl, isobutyl, cyclohexyl, phenyl, benzyl, 1-octenyl or 1-phenyl-1-heptenyl radical. 
     
     
       14. The process of claim 11, where X, in the cocatalyst of the formula (R IV ) n  AlX.sub.(3-n), is at least one of chlorine, bromine or iodine. 
     
     
       15. The process of claim 14, where X is chlorine. 
     
     
       16. The process of claim 11, where the cocatalyst of the formula (R VI ) n  AlX.sub.(3-n) is at least one of ethylaluminum dichloride, ethylaluminum sesquichloride or diethylaluminum chloride. 
     
     
       17. The process of claim 11 where the mole ratio of the cocatalyst to the transition metal complex catalyst is between approximately 1:1 and 300:1. 
     
     
       18. The process of claim 11 where the ratio of the organometallic compound cocatalyst to the transition metal complex catalyst is between approximately 3:1 and 50:1. 
     
     
       19. The process of claim 1, where the polyamide forming reactant is at least one of (1) an alpha, beta-unsaturated carboxylic acid and ammonia or (2) an ammonium salt of an alpha, beta-unsaturated carboxylic acid. 
     
     
       20. The process of claim 19 where the alpha,beta-carboxylic acid is of the formula ##STR14## where each R' is independently one of hydrogen, C 1  to C 4  alkyl group or a halogen and R" is one of hydrogen or a C 1  to C 10  alkyl group. 
     
     
       21. The process of claim 20 where the alpha,beta-carboxylic acid is at least one of acrylic acid or crotonic acid. 
     
     
       22. The process of claim 19 where the ammonium salt of the alpha,beta-unsaturated carboxylic acid is of the formula: ##STR15## where each R' is independently one of hydrogen, C 1  to C 4  alkyl or a halogen and R" is one of hydrogen of a C 1  to C 10  alkyl group. 
     
     
       23. The process of claim 22 where the ammonium salt of the alpha,beta-unsaturated carboxylic acid contains between 3 and 7 carbon atoms. 
     
     
       24. The process of claim 23 where the ammonium salt of the alpha,beta-unsaturated carboxylic acid is at least one of ammonium acrylate or ammonium methacrylate. 
     
     
       25. The process of claim 1, where the temperature sufficient to cause polymerization is between 100° C. and 300° C.